Sky HD stuck on one channel

[Archi11]

My sky HD box was working normally and I was viewing the channels normally

Suddenly I tried to change the channel but it didn't work and it's stuck on the channel I was watching. I tried unplugging it and connecting it again after a Couple of minutes but still when it operates back it's the same channel. 

When I press the number of the channel I want it says channel not available. Any idea what's wrong.

[Mark39]

Switch off at the plug and leave it for at least 4 minutes before switching on again.

[Archi11]

I've tried but nothing changed 

When I turned it back on it's still on the same channel and can't change it.

[Mark39]

You said a couple of minutes in your first post. It needs to be off at the plug for at least 4 minutes. Does the remote still control your Sky box, apart from not being able to change change channel? Can you still access the menus?

[Archi11]

Yeah I did it again for 5 minutes but still nothing

The remote doest control the box normally and can check the menu and the favourits but it shows only one channel that's on that can be added to favorites.

It's just when I try to get another channel it gives blue screen then shows the same channel and when I try to type the number of the channel it says not available

[Archi11]

Does control the box normally*

[Mark39]

Doesn't sound good. I suspect the box has failed. You could try a system reset via the Installer Menu (key services,0,0,1,select). but be aware that it will delete your recordings.  Otherwise give Sky a call.